#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>

#define DEMO_DEV_NAME "/dev/my_demo_dev2"

int main(){
    char buffer[64];
    int fd;
    fd = open(DEMO_DEV_NAME, O_RDONLY);
    if (fd < 0){
        printf("open device %s failed\n", DEMO_DEV_NAME);
        return -1;
    }
    read(fd, buffer, 64);
    close(fd);
    return 0;
}